Aspiring homeowners in San Francisco will need to save for nearly a decade to amass a 20 percent down payment, while mortgage rates have climbed to a four-year high. Check out the week's most notable housing-market headlines in Pacific Union's Real Estate Roundup.

Over the past decade and a half, more than 20 U.S. states have not built enough homes to meet demand, leading to rising prices and decreased affordability, with California accounting for nearly half of the undersupply.

San Francisco retained its title as America's hottest housing market in March, while a proposed ballot initiative could help ease California's housing inventory crunch. Get the lowdown in Pacific Union's latest weekly Real Estate Roundup.

More than one-third of the 25 most popular U.S. real estate markets for households with seven-figure annual earnings can be found in the Golden State, with San Francisco -- perhaps not surprisingly -- topping the list.